On Fri, Sep 12, 2025 at 3:54 PM jian he <jian.universality@xxxxxxxxx> wrote: > > > select v from t where v similar to 'foo[\d\w]_%'; > > > select v from t where v similar to 'foo[[[:digit:]][[:word:]]]_%'; > The above two examples are the same, per > (Table 9.21. Regular Expression Class-Shorthand Escapes) Of course. > my guess why 'foo0bar' will fail for 'foo[[[:digit:]][[:word:]]]_%'; > 1. process character 0, it does meet [[:digits]] character class. > 2. process character b, it does not meet [[:digits]], then fails, > it won't check again whether character b is satisfied with [[:word:]] or not. Then you don't know what [...] means in regexes I'm afraid. --DD
